Clanoptilus marginellus (Olivier, 1790)
A widespread European species distributed from Spain to the Caspian Sea and from Italy to southern Scandinavia; it was formerly widespread, although of very local occurrence, across southeast England from Norfolk to South Hampshire with a few records scattered to South Devon, but following a recent and drastic decline, probably due to modern farming methods and land management, is now confined to a few coastal areas of Kent, Sussex, Hampshire and the Severn valley. On the continent it is associated with open grassland or scrub with abundant flowers but in the U.K. it occurs on salt marsh and shingle with lush vegetation either on the coast or along river valleys e.g. sea sandwort, Honkenya peploides (L.) or seakale, Crambe maritima L., and in the Severn Valley it is associated with Hogweed, Heracleum spp. and Tansey, Tanacetum vulgare. Adults occur for a short period, generally four or five weeks, from May to July depending upon the season, and may be locally abundant among populations of other malachids e.g. Malachius or Cordelepherus. They may be found by sweeping vegetation or observing flowers where they fly between blooms during sunny weather, in overcast conditions they remain on the ground or low down on stems. Adults are thought to feed on pollen while the larvae are scavengers as well as predatory among decaying plant material including dead wood.
The large size and pale pronotal margins make this species distinctive among the U.K. fauna. 5-5.5mm. the dorsal surface is shiny metallic green or with the head and pronotum darker, sometimes black, and with recumbent pale pubescence and sparse erect black setae. Lateral pronotal margins and elytral apex yellow. Head smooth, with a transverse impression between the eyes, and the clypeus and labrum yellow. Palps yellow with the apical segment dark, antennae dark with at least the underside of the basal segments pale, the second segment small, remainder more or less equal in length; in the male the apices of segments 3-7 have a blunt tooth near the inner apical margin. Eyes entire and protruding. Pronotum quadrate with the lateral margins rounded, and explanate in the basal half. Elytra dull from microsculpture and fine punctation, the humerus well-developed and raised so that the lateral margin is not visible from above, and the apices separately rounded; in the male with a fine tooth. Legs long and slender; metallic green with pale tarsi, especially the pro-tarsi. Tarsi 5-5-5 without lobed segments. Claws smooth.